The correct answer is (c) Kanishka.
Kanishka was the second Kushan emperor, who ruled over a vast empire in Central Asia and the Indian subcontinent from around 127 to 150 CE. He was a great patron of Buddhism and is credited with spreading the religion throughout his empire. He also introduced gold coins for regular use in India, which had previously been used only for ceremonial purposes.
Vim Kadphises was the first Kushan emperor, who ruled from around 90 to 127 CE. He was a great conqueror who expanded the Kushan empire to include much of Central Asia and the Indian subcontinent. However, he did not introduce gold coins for regular use in India.
Kujulo Kadphises was the son of Vim Kadphises and the successor to Kanishka. He ruled from around 150 to 170 CE. He was a successful ruler who maintained the Kushan empire at its peak. However, he did not introduce gold coins for regular use in India.
Hermwes was a Kushan prince who ruled over a small kingdom in Bactria in the early 2nd century CE. He was not a major ruler and did not introduce gold coins for regular use in India.